Thermal Depolymerization Process oil has been around for a while. The process is designed to handle almost any waste product imaginable, including turkey offal, tires, plastic bottles, harbor-dredged muck, old computers, municipal garbage, cornstalks, paper-pulp effluent, infectious medical waste, even oil-refinery residues. There are actually three product streams: a form of natural gas, varying grades of petroleum (depending on the feedstock being reduced), and various minerals, either as elemental metals or oxides. The substance goes into the reaction retort vessel as a watery slurry, and cooking time is a matter of only a few hours. Actually, the superheated steam under pressure (two to five atmospheres) is what does the conversion. There is a serious amount of heat that has to be applied to start the process, but once under way, the gaseous volatiles are enough fuel to keep the process going in a series of other retorts, in various stages of the cook-down. The other problem is keeping the process supplied with feedstock material, much like an incinerator that burns trash for power generation. The kinds and composition of the feedstock have to be carefully monitored, but this is a doable technique. It would work very well on a high-volume sewage processing facility, for example, with no need for drying down the residue.
The main problem for the plants is transport of feedstock to a facility because they cant at this time be located anywhere near civilization. The smell is so hideous that the plants can be smelled from a million miles away (...OK, maybe not quite that far) which affects the overhead because everything needs to be transported so far.
The other problem that will be encountered that wont really be an issue until these are tried in any significant number is the public service unions. The minute garbagemen and sewage workers are threatened by "evil capitalists putting poor men out of work by taking advantage of free resources", every union will rise in solidarity with their fellow clowns. This will stop the places that are most likely to benefit, ie NYC, from being able to implement such a plan.
Excellent description, thanks! The unknown in my mind is the cost of the process verses getting crude out of the ground. Back when we were playing around with our little "experiment", the price of oil was around $30 a barrel and it didn't seem cost effective.